Psychology of the Polygraph Test

Psychology of the Polygraph Test

The polygraph test, introduced nearly a century ago, has been widely used in the detection of deception and for some time, has been considered by law enforcement representatives, an exceptionally valid testing apparatus. The media and law enforcement representatives describe the various methods of detecting deception to be extremely valid and reliable in detecting deceptive cues, although the various research done through field studies and controlled experiments demonstrate significant error rates amongst the various testing procedures used. Physiological responses of an individual may vary from person to person. No matter how small the error rate may be, there is always a chance that environmental conditions as well as physiological conditions induced by the individual or the interpreter can have an effect on the interpretational conclusion of what were considered to be deceptive cues. These influential factors may illustrate a small positive or negative error rate, but when the conclusion is applied to a conviction, it can possibly establish or distinguish false results to be accurate or inconclusive.

The implausibility of the various methods of the detection of deception poses an immense threat to the innocent. When we apply these results to a defendant on trial, these "false results" can be extremely detrimental to the case. False results can possibly allow the guilty to be liberated and the innocent to become incarcerated. The only way we can apply these tests and use the results as court evidence is if we can make the testing procedures 100% reliable. But, as research shows us, because of the numerous influential environmental, psychological, social, and physiological factors that can damage the validity of the results, the test results will remain obsolete in the eyes of the court.

Employment and interpretations of the polygraph poses as the greatest threat to the testing subject. It is generally agreed upon psychophysiologist's that there is no specific lie response. Basically, no specific action has been identified and allocated as an irrepressible deceptive cue. This seems to be very contradicting to the whole purpose of the polygraph test. The fact that the polygraph is wide open to interpretation crates invalidity from the start.

Although alterations have been made to protect the validity an minimize the error of the polygraph, the results are still dependant of the subjects physiological response. Although research has shown that these alterations do in fact minimize the inaccuracy of the results, no matter what changes are made, there is still a minimal possibility that one can wittingly breach the barriers.